The particular parameters of products to be cartoned place a host of varied demands on a cartoner. It is known to feed single or grouped product into buckets in a cartoner and to push the products from the buckets into erected cartons moving alongside the product bucket. However, variations in product delivery orientation, feed rate, flow direction, product size, product shape, packing orientation with respect to the carton parameters and flow or throughput speed all must be considered. A variation in any one of these parameters may render a cartoner unfit for cartoning where one of these parameters differs from that for which the cartoner is designed.
Delivery and insertion of flat trays into cartons presents unique cartoning parameters. Such flat thermo-formed trays for single-serve frozen foods or “T.V. dinners” are but one example of an elongated flat tray, typically sealed over with a clear plastic film or lid, and bearing a food product, which are to be placed each in a single carton of rectangular shape conforming generally in size, but not necessarily in shape, to the tray. Such trays are typically of semi-elliptical shape with opposed narrow blunt ends.
Cartons are preferably supplied to the cartoner in blank form, erected with at least one open end for receiving the tray, then closed, sealed and discharged. Where the cartons are erected and transported downstream alongside product buckets, the cartons are oriented such that their width dimension is oriented parallel to their downstream motion, and their longer length dimension is perpendicular to the downstream or machine flow direction.
Where the elongated trays are fed into the cartoner end-to-end with their elongated length parallel to the machine flow, i.e. with a narrow blunt end leading, and their width or sides extending between the blunt ends perpendicular thereto, the trays must be turned 90° so they can be pushed perpendicularly to the machine flow, blunt end first, into the open carton ends.
Positive indexing and turning of the trays while maintaining them under positive control presents handling obstacles, particularly at the high flow rates or throughputs desired in excess of 200 trays per minute and preferably at least 240 to 260 trays per minute and up to 300 trays cartoned per minute. It is desired to minimize changes in velocity and direction of the trays through the process at these speeds and to reduce tray damage during cartoning.
Accordingly, it is objective of the invention to provide improved apparatus and methods for cartoning flat trays.
Another objective of the invention has been to provide apparatus and methods for receiving abutting flat trays and indexing them for cartoning.
Another objective of this invention has been to provide apparatus and methods for turning flat trays for orientation in provided buckets for feeding adjacent cartons.
Another objective of the invention has been to provide methods and apparatus for cartoning flat, elongated trays at speeds in excess of 200 trays per minute while positively controlling the trays through carton insertion.
Another objective of the invention has been to provide apparatus and methods for receiving flat trays in end-to-end relation, indexing the trays and turning the trays for insertion into cartons.
A further objective of the invention is to transport an elongated, narrow end leading product into a cartoner station in a relatively straight machine flow vector or direction and to minimize the forces necessary to turn the product to an orientation with a broad side leading in the machine flow direction for transverse insertion into a carton with narrow end leading.
To these ends, the invention in one embodiment receives elongated flat trays in abutting narrow-end-to-narrow-end relation, indexes or spaces those trays for alignment between spaced product lugs of a first conveyor, engages a forward corner portion of the narrow tray end with a turning guide or cam, turns the trays about a pivot area on a trailing lug while urging the tray with the turning guide into a product bucket on a second conveyor, and thereafter pushing the trays from the buckets into cartons on an adjacent conveyor.
Elongated trays are delivered primed on a low pressure infeed conveyor. Pressure relief and/or metering apparatus, such as rotating star wheels or indexing belts control tray delivery onto a tray conveyor carrying the spaced lugs at a correct tray pitch. An optional hold-down guide oriented above the tray path prevents trays from climbing over the turning guide. The configuration of the turning guide acting on the trays is sufficient to gently introduce the trays into the adjacent cartoner bucket conveyor without need for additional transfer devices.
Preferably, the product buckets each have a leading wall tapered or inclined in rearward direction toward a rearward wall to define a wide bucket mouth and thus facilitate product indexing and turning product entry into the bucket.
These and other objectives, advantages and alternatives will be readily appreciated from the following detailed description and from the drawings in which: